Not Applicable
Not Applicable
The field of invention is switch lever lock outs for locking switch levers in a desired position, and more particularly to switch lever lock outs which have one end positively engaging the lever and another end engaging a fixed rail.
Switches are used in many applications to control the flow of electrical energy. The switches can be used to redirect electrical energy from one circuit to another, and can be used to stop the flow of electrical energy through a circuit. In both cases the circuits become de-energized, that is without a voltage. One particular type of switch is a circuit breaker which cuts off the flow of electrical energy when the flow of electrical energy through the switch exceeds a predetermined value. Many of these circuit breakers include a lever which is movable between an xe2x80x9cOnxe2x80x9d position and an xe2x80x9cOffxe2x80x9d position.
Maintenance personnel often use a circuit breaker to cut the flow of electrical energy through a circuit when the circuit, or electrical components connected thereto, require maintenance. The circuit breaker, however, is often remote from the location requiring maintenance. Therefore, it is desirable to lock out the circuit breaker to prevent an individual from inadvertently energizing the circuit while maintenance is being performed.
Known circuit breaker lock out assemblies engage the circuit breaker lever to prevent unauthorized movement of the lever. Lockouts, such as disclosed in U.S. Pat. Nos. 5,593,020; 5,794,760, and 5,900,600, include a lock arm cantilevered from a lock rail. The lock arm includes a head which engages or covers the circuit breaker lever to prevent unauthorized movement of the lever. This particular type of lock out can be easily circumvented by lifting the cantilevered head away from the lever to disengage the lever from the head. As a result, the lock out adequately serves to provide notice to an individual that movement of the lever is unauthorized, however, it is not always effective to prevent unauthorized lever movement.
Another disadvantage of the prior art cantilevered lock outs is the inability to lock out adjacent circuit breakers aligned along an axis perpendicular to the lock rail. Only one opening in the lock rail can be used to hold a cantilevered lock arm, and each lock arm can lock out only one circuit breaker. In addition, the prior art cantilevered lock out assemblies disclosed in the above referenced patents include components formed from different materials, or otherwise not easily formed using injection molding techniques to minimize fabrication costs. Therefore, a need exists for an effective switch lock out which can be fabricated using injection molding techniques.
The present invention provides a switch lever lock out assembly which is engagable with a switch having a lever positionable in at least two positions. The assembly includes a lock rail fixable relative to the switch. At least one transverse opening is formed in the lock rail. One end of an elongated lock arm extends through the opening and an opposing end extends toward the switch. In one aspect of the present invention, a switch engageable head is fixed to the lock arm opposing end, and is clampable to the lever. In another aspect of the invention, the head is slidably mounted to the lock arm. In yet another aspect of the present invention, the head is fixed to the lock arm, and offset from a lock arm longitudinal axis.
A general objective of the present invention is to provide a switch lock out assembly which is easily fabricated. This objective is accomplished by providing a lock out assembly which can be fabricated by injection molding.
Another objective of the present invention is to provide a switch lock out which is not easily circumvented. This objective is accomplished by providing a switch lock out assembly which includes a lock arm having a head which clamps onto the switch lever to prevent the head from being lifted off of the lever while the switch is locked out.
Yet, another objective of the present invention is to provide a switch lock out assembly which can lock out adjacent switches. This objective is accomplished by providing a switch lock out assembly which includes a lock aim having a head which is offset or slidably movable relative to the lock arm.
The foregoing and other objects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention.